Japanese older adults with diabetes or a BMI of less than 18.5 kg/m2 are more likely to develop dementia than those without either condition, according to findings published in the Journal of Diabetes Investigation.
“Clinicians need to evaluate the reasons for their patients being underweight and provide interventions according to their disease profiles,” Hiroshi Yokomichi, PhD, MD, MPH, DPH, associate professor in the department of health science at the University of Yamanashi in Japan, and colleagues wrote.
Yokomichi and colleagues performed a cohort study with 3,696 adults who were enrolled in the Japan Gerontological Evaluation Study in 2010 (mean age, 73.4 years; 57.2% women). All participants were aged at least 65 years and took part in a baseline medical examination during which measurements of blood pressure, cholesterol, HbA1c, weight and height were collected. These values were used to establish BMI status as well as if a participant had diabetes, hypertension or dyslipidemia, according to the researchers, who had access to follow-up data over an average of 5.8 years. This information along with data from the long-term care insurance system helped identify instances of dementia.
Dementia was diagnosed in 338 of the participants during the study period. Men with diabetes were more than twice as likely to have dementia (HR = 2.22; 95% CI, 1.26-3.9) as men without diabetes, and women with diabetes were also at greater risk compared with women without diabetes (HR = 2; 95% CI, 1.07-3.74).
Japanese older adults with diabetes or a BMI of less than 18.5 kg/m2 are more likely to develop dementia than those without either condition.
“Presumed mechanisms for the high dementia incidence in patients with diabetes include oxidant stress from steep glycemic excursion and production of reactive oxygen species, reduction of insulin transportation to the brain, inflammation of cerebral tissue, reduction of insulin signaling, and atherosclerosis from hypertension and hypercholesterolemia,” the researchers wrote. “These data suggest that controlling diabetes in older adults would contribute to reducing the risk for dementia.”
Dementia was also more likely for women with an underweight BMI of less than 18.5 kg/m2 (HR = 1.72; 95% CI, 1.05-2.81) and men with underweight (HR= 1.04; 955 CI, 0.51-2.1), although the researchers noted that this association was significant only in women. Hypertension in women (HR = 1.05; 95% CI, 0.64-1.71) and dyslipidemia in men (HR = 1.3; 95% CI, 0.87-1.94) increased dementia risk numerically. However, when hypertension was combined with a BMI of 18.5 kg/m2 in women, the risk was more than three times higher vs. women with a higher BMI and without dyslipidemia (HR = 3.79; 95% CI, 1.55-9.28). In addition, men with dyslipidemia and a BMI of less than 18.5 kg/m2 were four times more likely to have dementia compared with those with higher BMI and no dyslipidemia (HR = 4.15; 95% CI, 1.79-9.63).
“The high risk for dementia among those with low BMI in the present study emphasized the importance of maintaining muscle mass to preserve cognitive function,” the researchers wrote. “This suggests that it might be important to encourage older adults to consume more protein than younger to middle-aged adults.” – by Phil Neuffer
Disclosures: The authors report no relevant financial disclosures